Their audit showed outlets with a left-wing audience had 62.4 per cent of all article views compared to 11.3 per cent from the right. Even when accounting for stories that weren’t rated as having right or left readers, the researchers say the trend is still clear.

The monopolization also became more apparent with certain searches. CNN and The New York times racked up three of four article views in a search for “rex tillerson.”

So does Google like the political left more than the right? Not quite.

“The underlying issue in source diversity appears to hinge on a greater availability of news material on the left,” wrote Trielli and Diakopoulos.

One factor that influences the search engine’s algorithm is how often a newsroom makes content. If an outlet publishes more stories at a faster rate, Google’s algorithm takes notice.

To be clear: our research does not say that Google prefers any type of ideology when it comes to sources. What it does say is that, whatever the choices of the algorithm, it ends up concentrating attention to a few sources, and that has implications in ideological diversity. 2/3

Newsrooms with left-wing readers produce twice as many stories as their counterparts, but Google seems to exaggerate the difference to three times as many stories, which means those articles end up in the Top Stories box more often.

Outlets with more of those Top Stories views get more traffic on their website. A rough estimate shows CNN enjoys a 24 per cent bump in website visitors compared to NPR, which sees just under four per cent.

Trielli and Diakopoulos can’t determine why only a few outlets have a stranglehold on search results. In their report, they say it could just be a matter of having a higher search ranking by the algorithm or simply being better at getting content noticed.

For its part, Google explained the algorithm chooses how to rank stories based on the reliability and popularity of the source, as well as how old or relevant the article is to the search terms.

“We have no insight into the methodology these researchers used,” a Google spokesperson wrote in an email to the National Post.

“Other researchers have found exactly the opposite. The fact is that like Google search and Google News, our Top Stories feature has absolutely no signal for a story’s political point of view.”

This study comes amidst the tech giant’s decision to ban political ads on all its platforms and the launch of a new website to add more transparency to its news function.